Suzuki Sayaka, Manzello Samuel L
National Research Institute of Fire and Disaster, Japan.
National Institute of Standards and Technology, USA.
Fire Technol. 2020;56(5):2315-2330. doi: 10.1007/s10694-020-00982-2.
Roof assemblies are known to be vulnerable to firebrands in urban and wildland-urban interface fires. In the 2016 urban fire in Japan (Itoigawa-City Fire), at least 10 structures were ignited by firebrand showers and three of these structures were ignited by firebrand penetration under tile roof assemblies. In this study, the vulnerabilities of Japanese-style roof tile assemblies to firebrand exposures were investigated by using a continuous-feed firebrand generator with applied nominal wind speeds of 6 m/s and 9 m/s. It was observed that Japanese-style roof tile assemblies were more vulnerable than concrete flat, concrete profile, and terracotta flat roof tiles for applied wind speeds of 6 m/s. When the experiments were performed with debris placed underneath the roof tiles, penetrated firebrands ignited debris. Flaming ignition was observed under 9 m/s where flame was observed to protrude from the tiles in an effort to reach necessary oxygen for combustion.
众所周知，在城市火灾和城市与荒野交界处的火灾中，屋顶组件容易受到火brand的影响。在2016年日本的城市火灾（糸鱼川市火灾）中，至少有10座建筑物被火brand阵雨点燃，其中3座建筑物被瓦屋顶组件下的火brand穿透点燃。在本研究中，通过使用连续进料火brand发生器，在6米/秒和9米/秒的标称风速下，研究了日式屋顶瓦组件对火brand暴露的脆弱性。观察到，对于6米/秒的应用风速，日式屋顶瓦组件比混凝土平瓦、混凝土型材瓦和赤陶平瓦更容易受到影响。当在屋顶瓦下方放置碎片进行实验时，穿透的火brand点燃了碎片。在9米/秒的风速下观察到有火焰点火现象，此时火焰从瓦片伸出，试图获取燃烧所需的氧气。
